Key facts
- US copper stockpiles exceed 1 million metric tons.
- Comex-approved warehouses hold about 70% of the world's visible copper stocks.
- The arbitrage for shipping copper to the US is now about $310 a ton.
President Donald Trump's threat of tariffs has led to a significant build-up of copper stockpiles in the United States, exceeding 1 million metric tons. This has resulted in Comex-approved warehouses holding approximately 70% of the world's visible copper stocks, creating shortages elsewhere and driving up prices. Traders began shipping copper to the US after Trump ordered a tariff study in February last year, creating a profitable arbitrage opportunity. However, this arbitrage has since collapsed, with the current gap at about $310 a ton, weakening the incentive to move more metal to the US. The US Commerce Department was expected to report on the domestic copper market by June 30, allowing Trump to decide on imposing a 15% tariff on refined copper imports from January 1, 2027, potentially rising to 30% in 2028, but no decision has been announced.